A Motorola developed CAD system provides the crit-ical interface between Motorola's Bipolar LSI Operationsin Mesa, Arizona and engineers doing MCA option de-velopment. The CAD system is contained in a Motorolacorporate computer system and operates through tele-phone lines to graphics equipment (Tektronix 4014 Com-puter Display Terminal and 4662 or 4663 plotter) at theuser's location.

The Macrocell Array CAD system provides the follow-ing benefits:

1. All worksheets for option development.

2. Interactive graphics for accepting design infor-mation. Option data can be digitized on the plotter orentered through the CRT screen.

Each MCA option is customized by selecting macrocellfunctions from the library and placing them in cell lo-cations on the array chip, and by interconnecting macro-cells to each other and to I/O bonding pads. Cell place-ment and routing can be entered manually through theCRT terminal and/or plotter, generated automaticallywith place and route software in the CAD system, or acombination of both manual and automatic to optimizea particular design. Although the CAD system flags de-sign rule violations, MCA macrocell selection, placementand routing accuracy remains the user's responsibility.

A final user design requirement is to provide a func-tional test sequence. The CAD helps again by allowingthe designer to exercise a possible test sequence with asimulated model of the array. It also provides a faultgrade program which allows the user to determine anyarray logic not tested by a given test sequence.

The CAD flow diagram in Figure 7 provides moredetail on CAD system operation. Starting with a devel-opment contract in the upper right corner, Motorola andthe array customer agree on number of options, timeschedules, and business terms. At this point, the userreceives a password into a Motorola computer systemand is ab ' t to access CAD software over phone lines ona time share arrangement. CAD software includes in-terface to the 4014 graphics system, MCA operating sys-tem with the macrocell library and routing data entry,simulation based on LOGCAP software, interface toMotorola CALMA graphics and final test systems, andthe MCA automatic route and placement program.

While using graphics equipment, the option designerfollows a sequence of design steps. The following list isbased on Motorola's automatic place and route software:

After the customer's option design is complete,Motorola translates option data to semiconductor metaland via mask sets through a CALMA graphics system.Wafer processing is then completed using wafers whichcan be produced in quantity and banked waiting for cus-tomizing metal. Finished wafers are tested at wafer probeusing the customer defined test sequence located in theCAD system and Motorola added parametric testing.Packaged parts are final tested and good parts shippedfor customer evaluation.

An important feature of the MCA CAD system is theability to handle all design operations unique to manu-facturing an integrated circuit product. Option designwork performed by the customer including logic defini-tion, placement, metal routing, and test tables are allcommon to designing a printed circuit board. The CADsystem handles interconnecting transistors and resistorsinto logic blocks, selection of first and second layer metal,metal widths and spacing, via locations and sizes, powerdistribution, shorting unused gate inputs, and other ICrelated tasks.

HARDWARE DESCRIPTION

Macrocell array CAD software is resident on IBM com-patible computer systems located in Scottsdale, Arizonaat the Motorola Western Area Computer Center (WACC).CAD software is available to macrocell array customerson a time-share basis over normal telephone lines ordatacomm network at 300 or 1200 baud data rates.

the user to interface with WACC computers in a mannerunderstandable by both computer and human operator.By typing on the keyboard, a macrocell array option de-signer can instruct CAD software to perform variousmacrocell array design functions. The CAD system com-puter response is returned to the operator by way of adisplay screen, either alphanumerically or graphically.The terminal also communicates with the plotter unitand acts as a link between computer and plotter.

Tektronix 4662 or 4663 Interactive Plotters generatemacrocell array worksheets and permanent design rec-ords. The plotters may also be used to digitize routinginformation into the CAD system. The 4662 accepts pa-per sizes up to 11 by 17 inches, while the larger 4663handles paper up to 17 by 22 inches. Both the 4662 and4663 plotters are connected in series between the 4014/4014-1 graphics terminal and the telephone modem.

Several CAD array design operations do not requiregraphics interface. These include logic simulation, faultgrade, design verification, and generating a net list forautomatic route and place software. Although the4014-1 terminal and hard copy unit could be used, a TTYcompatible terminal (TI Silent 700 or equivalent) hasproven more convenient. The terminal must communi-cate in ASCII format and operate at 300 or 1200 baudrate.